Recent research from Southampton University showed links between seven common E numbers and behavioural problems in children.

Cadbury will remove all artificial colours from its entire range of sweets by the end of next year.

Starburst

Rival confectionery firm Mars will remove artificial colours from Starburst sweets by the end of this year.

All artificial colours mentioned in the Southampton University report will be removed from Skittles by the end of this year.

Mars said in a statement: 'We will continue to review the use of additives in our brand portfolio. All additives are clearly listed on the packs.'

A Cadbury spokesman said: 'We are committed to replacing all artificial colours in our sweets. We note the Southampton University findings, but we had begun this process already because we are continually listening to our consumers.'

Hyperactivity

The Food Standards Agency changed its advice to parents last week after the study showed that normal children given a cocktail of additives behaved impulsively and lost concentration.

It says children showing signs of hyperactivity should cut certain additives from their diets.